<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        function sun(a) {
            var zu = a[0];
            for (var i = 1; i < a.length; i++) {
                if (a[i] > zu) {
                    zu = a[i]
                }
            }
            return zu
        }
        console.log(sun([4, 5, 9, 8, 10, 12]));
    </script>
</head>

<body>

</body>

</html>